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LG 505E Series Service Manual
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LG 505E Series Service Manual

LG 505E Series Service Manual

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COLOR MONITOR
SERVICE MANUAL
CHASSIS NO. : CA-138
MODEL: 505E
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MENU
SELECT
E-mail:http://www.LGEservice.com/techsup.html
(505EM-KL***L*)
Website:http://biz.LGservice.com
**
(
)
Same model for Service

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Summary of Contents for LG 505E Series

  • Page 1 Website:http://biz.LGservice.com E-mail:http://www.LGEservice.com/techsup.html COLOR MONITOR SERVICE MANUAL CHASSIS NO. : CA-138 (505EM-KL***L*) MODEL: 505E CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. MENU SELECT Same model for Service...

  • Page 2: Table Of Contents

    CONTENTS SPECIFICATIONS ........... 2 ADJUSTMENT ............9 SAFETY PRECAUTIONS ........3 TROUBLESHOOTING GUIDE ......16 SERVICE PRECAUTION ........4 EXPLODED VIEW........... 31 WIRING DIAGRAM ..........7 REPLACEMENT PARTS LIST ....... 32 BLOCK DIAGRAM ........... 8 SCHEMATIC DIAGRAM......... 37 DESCRIPTION OF BLOCK DIAGRAM.....9 PRINTED CIRCUIT BOARD........

  • Page 3: Safety Precautions

    SAFETY PRECAUTIONS SAFETY-RELATED COMPONENT WARNING! X-RADIATION There are special components used in this color monitor The only potential source of X-radiation is the picture tube. which are important for safety. These parts are marked However, when the high voltage circuitry is operating on the schematic diagram and the replacement properly there is no possibility of an X-radiation problem.
  • Page 4 SERVICING PRECAUTIONS CAUTION: Before servicing receivers covered by this 9. Use with this receiver only the test fixtures specified in service manual and its supplements and addenda, read this service manual. and follow the SAFETY PRECAUTIONS on page 3 of this CAUTION: Do not connect the test fixture ground strap publication.
  • Page 5 General Soldering Guidelines Replacement 1. Use a grounded-tip, low-wattage soldering iron and 1. Carefully insert the replacement IC in the circuit board. appropriate tip size and shape that will maintain tip 2. Carefully bend each IC lead against the circuit foil pad and solder it.
  • Page 6 Circuit Board Foil Repair At Other Connections Excessive heat applied to the copper foil of any printed Use the following technique to repair the defective copper circuit board will weaken the adhesive that bonds the foil pattern at connections other than IC Pins. This technique to the circuit board causing the foil to separate from or involves the installation of a jumper wire on the "lift-off"...

  • Page 7: Wiring Diagram

    WIRING DIAGRAM P501(option) P701 P702 S + S P402 Socket P902 Signal Cable P302 P301 - 7 -...

  • Page 8: Block Diagram

    BLOCK DIAGRAM Dynamic Foc us Static Focus Screen - 8 -...

  • Page 9: Description Of Block Diagram

    DESCRIPTION OF BLOCK DIAGRAM 1. SMPS(Switching Mode Power Supply) 5. D/D Converter Circuit. When you turn on the power switch, the operating To obtain constant high voltage, this circuit supplies procedure is as follows: controlled DC voltage for FBT and horizontal deflection 1) The AC line voltage is rectified by the bridge diode circuit according to the horizontal sync frequency.
  • Page 10 DESCRIPTION OF BLOCK DIAGRAM 14. Video Processor Circuit. 15. Video Pre-Amp Circuit. Video processor circuit consists of the video drive This circuit amplifies the analog video signal from output block. The video drive IC(IC302) receives the 0~0.7 V to 0~4 V. It is operated by taking the clamp, video signal from PC.

  • Page 11: Adjustment

    ADJUSTMENT 1. Preparation for Service Adjustment 2. Adjustment by Service Hot key How to enter SVC HOT KEY GENERAL INFORMATION 1. Press Menu and OSD window will appear. 2. While OSD window is displayed, is seen on the All adjustment are thoroughly checked and corrected left bottom of OSD window.
  • Page 12 4. Distortion 10. Parallelogram Scanning frequency : All Mode (Mode 1~4) Display image : Crosshatch pattern Horizontal : 10 Row Vertical : 8 Row 11. Adjustment of white balance (Adjustment of chromaticity diagram) *(Adjustment of white balance must be made after entering Hot Key Mode and DEGAUSS.) 2.0mm, 2.0mm...
  • Page 13 11-2. Adjustment of White Balance PROCEDURE After finishing adjustment of cut off (back raster), For trained and experienced service technicians only. approve "Color(15.0) Full white pattern". Use the following procedure to correct minor color Adjust BDRV Data = 80, SCON=127. purity problems: Adjust RDRV and GDRV to set chromaticity diagram at : x: 0.283 0.005...
  • Page 14 3. Adjustment Using Service software Program 2. Adjustment for White Balance and Luminance. (Adjustment Program) 1) Set the White Balance Meter. 2) Press the DEGAUSSING on the OSD menu for 1. Adjustment for Factory Mode (Preset Mode). demagnetization of the CDT. 3) Display color 0,0 pattern at Mode 4.
  • Page 15 4. EDID Data Edit Using Service software Program 4.1 Read and Modify EDID Data 1) Connector the monitor and adjust device as Figure1 2) Display color 15,0 cross hatch pattern at Mode 4. 3) Use EDIT – MODEL SEL. command to select the right model info file. 4) Use EDIT –...

  • Page 16: Troubleshooting Guide

    TROUBLESHOOTING GUIDE 1. NO POWER NO POWER (POWER INDICATOR OFF) TROUBLE CHECK IN FUSE (F901) FUSE OK?(F901) SMPS Switch (ON, OFF) CHECK TROUBLE IN D900 BRIDGE DIODE? BRIDGE DIODE (D900) CHECK C908(+) VOLTAGE TROUBLE IN 145VDC at 110V input IC901, Q901 310VDC at 220V input IC901, Q901 CHECK...
  • Page 17 2. NO CHARACTER NO CHARACTER TROUBLE IN CHECK P301, SIGNAL CABLE, IC302 PIN 5,6,7 PC SIGNAL CHECK TROUBLE IN IC302 PIN 1, 24, 23, 19, 20, 21 IC302, P301 PIN 18 (5V) ? CHECK IC303 PIN 1, 2, 3 TROUBLE IN PIN8 (8V), IC303 PIN 4 (80V) ?
  • Page 18 3. NO RASTER NO VIDEO (POWER INDICATOR GREEN or FLASH) CHECK FLASH TROUBLE IN POWER INDICATOR P302 SIGNAL CABLE GREEN or FLASH ? GREEN CHECK ROTATE SCREEN CONTROL SCREEN CONTROL KNOB TO CLOCKWISE KNOB OF FBT or COUNTER CLOCKWIES CHECK VOLTAGE AT D961 CATHODE (50V) TROUBLE IN PRIMARY...
  • Page 19 4. NO VERTICAL DEFLECTION NO V-DEFLECTION (ONE HORIZONTAL LINE) CHECK TROUBLE IN IC601 Pin 3 (13V) ? T901 13V Line CHECK TROUBLE IN IC601 PIN 7 (45V)? T701 40V line CHECK TROUBLE IN IC401 PIN 33, 34 IC401 (SAWTOOTH WAVE)? TROUBLE IN IC601, V-CIRCUIT Waveforms...
  • Page 20 5. TROUBLE IN DPM Stand-by/SUSPEND/ DPMS OFF MODE FAILURE CHECK CHECK PC, INPUT H/V SYNC SIGNAL IC401 (MICOM) (PC IS NOT GOING INTO DPM PIN 52, 53 (H/V INPUT) MODE) SIGNAL? NO H/V SYNC SIGNAL CHECK TROUBLE IN IC401 PIN 45, 46 X401, IC401 WAVEFORM? CHECK...
  • Page 21 6. NO DEGAUSSING NO DEGAUSSING CHECK TROUBLE IN IC401 PIN 4 (5V)? IC401 (MICOM) CHECK TROUBLE IN Q953 COLLECTOR D953 VOLTAGE (0.5V)? CHECK TROUBLE IN P902? P902 TROUBLE IN CHECK RL901 RL901? TROUBLE IN TH901, DEGAUSSING COIL - 21 -...
  • Page 22 7. H_Deflection Failure 1. Check IC401 Pins 39,40,41 IC401 Pin 18 waveform is right? 2. Replace IC401. Q719 drain Check Q720,50V LINE waveform is right? D710 Q705 drain Check Q704 waveform is right? Check 13V line. Check and replace T703 Q706 base, collector and Q706.Check DY connector waveforms are right?
  • Page 23 8. TROUBLE IN H-LINEARITY UNBALANCED OF H-LIN. CHECK TROUBLE IN IC401 IC401 (MICOM) PIN 11,12 ? CHECK TROUBLE IN Q711~Q716? Q711 ~ Q716 CHECK TROUBLE IN L703? L703 Cs SIGNAL TABLE HORIZONTAL FREQUENCY(fH) 30K ~ 33.9K TROUBLE IN 34K ~ 38.9K C722, C726, C729 39K ~ 43.9K 44K ~ 48.9K...
  • Page 24 9. Abnormal H_Size The Voltage Repeat the troubleshooting waveform Q706 Collector Guide of H_deflection failure. is right? T701 pin 2 voltage Check D/D converter circuit is change with H frequency? Check IC401 B+ control circuit. 10. Side Pin or T rap Failure Check if AC Voltage of IC401 Pin 35 Check and replace IC401.
  • Page 25 12. Tilt Failure (optional) Check tilt connector connection IC401 Pin 26 output duty varies with Check and replace IC401. different DAC values? Q501 Emitter output varies Check Q503,Q501,Q502. with different DAC values? Check and replace CRT. 13. V Size or Pos. V ariation Failure IC401 Pin 33, 34 Check some parts around IC401.
  • Page 26 14. High Voltage Failure Q719 drain Check Q719,Q720 waveform is right? Check 50V line Repeat the troubleshooting Q706 collecter waveform Guide of H_deflection failure. is right? Replace T701 Waveforms Q719, Drain Q706,Collector 15. ABL Failure Input full white pattern to monitor. IC302 Pin22 Check and replace IC302 input exists and varies...
  • Page 27 16. Micom Failure IC401 Pin 16 input is over Check Q903,D908,ZD902 4.2V? IC401 Pin 45 and 46 Check X401 inputs are right? Check and replace IC401 Pin 23 input is R451,C408 High Active? All in/output values are Replace IC401. right? Done.
  • Page 28 18. User Control Failure Check connector Ass’y. IC401 Pins 27 and 28 Check and replace function key. inputs are right at each function? Check and replace IC401. Done. 19. Missing Color Proper Video levels are Check signal generator and on P301 Pin 1, 3 and 5. signal cable.
  • Page 29 20. Visible Retrace Check white balance adjustment. G2 voltage is right? Check G2 control volume and FBT. Blank pedestal is on Check IC302 Pin 19, 20 and 21 of IC302 and related components. Check Q799 Is V_FLB and DC_bias on and related components.
  • Page 30 22. Misconvergence Degauss the CDT Adjust Pole4,Pole6 Done to improve the misconvergence Change CRT and readjust convergence. Done. 23. Poor Focus Adjust focus VR. Aging monitor and Improved focus? check for focus change. Check focus leads from FBT to CRT Socket. Check the CRT Socket.
  • Page 31 - 31 -...

  • Page 32: Exploded View

    Ref. No. Part No. CABINET ASSEMBLY, 500EJ BRAND 3090TKB027A (RU) 3091TKB031Q 3091TKB048Q CABINET ASSEMBLY, 500EJ BRAND B031 320T 85964 LG (EU) 6318L15015A CDT(CIRC) M41LFQ803X00NGAA LG-PHILIPS 70KHZ 29.1MM FST MPR BARE(RU) 6318L15014B CDT(CIRC) M36LBL503X00NDDP LG-PHILIPS DI(EU) BACK COVER ASSEMBLY, 505EJ 3808TKB032A (LGENT)

  • Page 33: Replacement Parts List

    REPLACEMENT PARTS LIST CAUTION: BEFORE REPLACING ANY OF THESE COMPONENTS, READ CAREFULLY THE SAFETY PRECAUTIONS IN THIS MANUAL. * NOTE : S SAFETY Mark AL ALTERNATIVE PARTS MODEL :505EM DATE:2005.06.11 MODEL :505EM DATE:2005.06.11 PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO PART NO.
  • Page 34 MODEL :505EM DATE:2005.06.11 MODEL :505EM DATE:2005.06.11 PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO C 9 1 4 0 C Z Z T F T 0 0 1 P ECQB1H153JM3 153J 50V TP5.0 4A 150A 45NSSEC 10UA M A T S U S H I T A D 7 0 4 0 D R F C 0 0 0 1 0 A “FFPF04F150STU,LF FAIR CHILD ST...
  • Page 35 MODEL :505EM DATE:2005.06.11 MODEL :505EM DATE:2005.06.11 PART NO. DESCRIPTION/SPECIFICATON PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO F B 9 0 3 6 2 1 0 T C E 0 0 3 P BRS2550B BO SUNG 2550MM RADIAL R 3 0 1 0 R D 0 7 5 2 Q 6 0 9 75 1/4W(3 5% TA52 F B 9 0 5...
  • Page 36 MODEL :505EM DATE:2005.06.11 MODEL :505EM DATE:2005.06.11 PART NO. DESCRIPTION/SPECIFICATON LOC NO PART NO. DESCRIPTION/SPECIFICATON LOC NO R 4 4 1 0 R D 3 3 0 2 Q 6 0 9 33K 1/4W(3 5% TA52 R 7 7 3 0 R D 3 3 0 2 A 6 0 9 33K OHM 1/2 W(7.0) 5.00% TA52 R 4 4 2 0 R N 3 9 0 1 F 4 0 9...
  • Page 37 MODEL :505EM DATE:2005.06.11 MODEL :505EM DATE:2005.06.11 PART NO. DESCRIPTION/SPECIFICATON PART NO. DESCRIPTION/SPECIFICATON LOC NO LOC NO 1 5 ” ” ” T 7 0 3 6 1 7 0 T C Z 0 1 5 A “EI-19 4.45MH H-DRIVE,700BJ” T 9 0 1 6 1 7 0 T M Z 1 5 3 A EER3435 300UH V-16PIN T710BL SI/SC/NY/JS /TC 71-85KHZ...
  • Page 40 JUNE. 2005 P/NO : 38289S0010A Printed in China...

This manual is also suitable for:

505em-kl l series